The gibberella ear rot fungus produces a number of mycotoxins that are harmful to animals. These include deoxynivalenol (Vomitoxin), zearalenone and T-2 toxin.

Many Midwest grain elevators are now testing corn for traces of vomitoxin, which can cause kidney or liver damage as well as nervous system failure and death in infected cattle and hogs.

Vomitoxin has been now found in corn at grain elevators in northern Indiana and northern Ohio, according to a dealer who sells rail cars of corn to pet food makers in the southern U.S.

"One car had 27 parts per billion (ppb) and they rejected it," the dealer told Reuters News Service[7] last Thursday. "The pet food people are the ones who are very picky about it." Like milk producers, pet food makers typically reject corn with anything more than 20 ppb of the toxin.

There were previously reports that corn samples from points around eastern Iowa, northern Illinois and Wisconsin were testing positive for vomitoxin.

The fungus that causes fusarium ear rot can secrete mycotoxins called fumonisins into grain.

Plant specialists say that diplodia ear rot does not appear to cause mycotoxin contamination, but animals do refuse to eat grain with high levels of diplodia-damaged kernels. Additionally, severely affected grain has low nutritional value.

Iowa State University plant pathologists Alison Robertson and Gary Munkvold said last week that they had also started to receive reports of cladosporium[8] ear rot. Cladosporium, which is difficult to distinguish from trichoderma ear rot, is often associated with hail, insect or frost damage.